Regulator for electric generators



Dec. 18, 1923,

C. P. STEINMETZ ET AL REGULATOR FOR ELECTRIC GENERATORS JuIV; 29, 1915 I2.

4 Inventors Charles F? Steinmetz, Reinald 6.8 nderwlck,

Their fittqrneg,

Patented Dec. 18, 1923.

uNl-rEn s'fATcs PATENT oFmcE.

CHARLES I. STEINMETZ, OF SCHENECTADY. NEW YORK, AND REGINALD G. ASSIGNOLRS TO GENERAL ELECTRIC WICK, 0F LYNIQ, MASSACHUSETTS, A CORPORATION OF NEW YORK.

REGULATOR FOR ELECTRIQ GENERATORS.

Application filed July 29, 1915.

To all ache in it may concern lic it known that we, Ciiluucs l S'ri-nx- ME'rz, a citizen of the United States, resid ing at Schcnectad county 01 Schenectady, State of New York, and ltnomnnn (1. STANDERWICK, a subject of the King of Great Britain, residing at Lynn, county o't Essex, State of Massachusetts, have invent-- ed certain new and useful Improvements in Re ulators for Electric Generators, of

. Which the following is a specification.

Our invention has reference to a system of control for an electric generator, and is particularly applicable to small turbo-generator sets such as are used for train lighting, although it will, of course, be understood that our invention is not limited in its applications to situations of this character, but is ca able of general application.

urbo-ge'nerators have heretofore been employed on locomotives for supplying the electrical energy necessary for operating electrical translating devices such as, for ex ample, a headlight and cab lights, the turbine which operates the generator receiving steam from the locomotive boiler. In installations of this character the load is subject to considerable variation, as happens when either the cab lights or the headlight. is lis-- connected from the circuit and when the generator and turbine are designed to supply the translating devices with current at their rated voltage at full load, then when the load is decreased the speed of the till bine and of the enerator connected thcrw to is increased, with the result that the \'olt-- age on the lamps is increased, and this. of course, results in a short lite for the lamps; and, aside from the additional expense oocasioned' thereby, their premature burning out is likely to occur at times when it is difiicut or nnpossible to renew them or give them attention, and their failure is exceedingly inconvenient, and may lead to serious consequences. It has heretofore been proposed to ron- .trol"the s eed of the prime mover by :1

- centrifuga ly operated device that regulates the amount of steam admitted to the turbine, but such devices are open to the objection that they are likely to get out of Order, and are particularly obect-ionable for use in connection with turbo-generator sets Serial No. 42,548.

In accordance with our invention the voltage of the generator is innintained substantialtv constant by an artificial load. which is applied to the generator eith r when a port of the normal load is remorse. or in case of overload; but under norinel full load conditions the artiticinl load is moved.

()ur invention consists in providing an electromngneticnlly operated hrnlr for the generator,- providcd with a magnet; Winding, connected in shunt to the nerat and n. winding connected series therewitl'i. which is preferably nrrnngec, under norr' l full load conditions, to completely neutralize the shunt winding. 'i he electromagneti- Cally operated brake is the." fore under joint control of the. generator voltage end of the load current. in the preferred form of our invention, the electroinngueticnlly a. erated brake ot' the magnetic drag 1 although it will be understood that our vention is not limited thereto.

For. a fuller understanding our invention, reference may be hud to the ncconr section: lnntic \ltW showiu; the circuit and Fig. i) is no end ricw oi magnet ic lu'nltc shown in Referring, now. to the turbine which may receive locomotive at constant pre reducing valve in a well know i The :i rzune 12 ot' the turbogencrntor or supported by legs 3 ant One end of (mine comprises a cylindrical portion which with a transverse member 2" and end piece 2" constitutes a housing For the generator. The shaft 5 of the turbine is suitably journnled, as at (3, in the frame of the machine, the generator end of the shaft being enclosed by a hood 7. The armature 8 of the generator is mounted directly on the shaft The generator is preferably compounded for substantially constant po- 'tential under Variable load, and for this tagc will be below the normal l'ull load vl purpose is provided with a series field wind- 'tagzc and will t: *aduall rise to its norrnal ing 9 and ashunt licld winding 10. The alue Without injury to the system. With particular machine illustrated is bipolar, the shunt winding thus arranged and with and one of the pole-pieces is shown in lotthe series Winding arranged to neut 'alizce the cili'cct ot the shunt winding under normal 'l'ull load conditions. l have found that the current in the series winding may actually he decreased when the machine is short circuitcd and the machine accordingly made to run cooler under short circuit conditions than under full load conditions. important leaturc of applicants invention especially when it is used on locomotives Where short circuits are of frequent occurrence. it will be apparent, therefore, that the series winding: not only cooperates with the shunt winding to maintain the speed of the generator and the Voltage on the system Withinthe desired limits, but that the series coil also acts as a protective device against excessive currents in case of short; circuit on the machine.

ln accordance with'the provisions of the patent statutes, we have descrihed the principle ot operationot our invention together with the apparatus which we now consider to represent the best embodiment thereof.

Lb to be understood, however, that such ted lines in. Fig. 1. The generator is con nected by sngply conductors ll and l2 to the Worr. .55 load. 13. which usually coinprisesa headlight and cab-lights, and may comprise other tran lat 1g devices. its snown in the drawin the electromagnetically operated t 'a re has a field nieniher it having pole pieces i l (see 8) extending outwardly nearly to the cylindrical member 2, which. is secured by nicans ot a hub to the frame 2 of the generator. The member l-l forms, with the portion 2 or the frame a space within which a magnetizingwinding 1%, connected in shunt to the generator; and a series winding l"? are received. fin armature 18 of conductingn1aterinl which is preterahly composed of copper in the form oi? cup-shaped disc has a flange 19 extending between the port-ion '22 of the frame and the poles oi the hold incinher 14: and is secured t o the shatt The series coil is so designed with refer ence the shunt coil to completely ncntralinc the inng'necic action. of the shunt coil in ver nor ial full load tfii'ztlitioils. changes as come Within the spiritand scope lion, in case part or all or the load of the appended claims may be made.

is renioi'cd from the generate tn speed What We claim new and desire to of ti e generator tends to n vass i; cnreby Letters Patent of the United States, by causing an increase in the voltage across is the brushes 01" the gen rator and \on in i i. comhinatioinan electric generator,

a load circuit connectel thereto, and means for limiting both the voltage and the current of the load circuit comprising an electi'G-lllfigZJHQillC hrahe operated by two oppositely directed TilHKQS responsive to "the vol crease in he niagncti'iz oi? thc shunt 'Winoir' at the time, the current in coil is decreased. Thcshnnt-coih I rpowers "the series coih and a magnetic i fiwhich tends to sets up A to maintain the speed oi the generator suhtage and the current respectively o the load S'uttllhlilllff constant. 'U-n 'LliG other hand in circ and neutralizing eaqhnther nnde case or overload or in case oi sin "t circnih normal loll load conditions. I i

the inerator no tend to supply more cnrin a system 01?? control, an electric genre t, out. ini'niedi this more Hive current orator, load circuit connected theieto,-and

rneans ror maintaining the voltage of said generator substantially constant comprising an electroinognetically operated brake for the generator gene tor voltage and. of the load current. oi .n at system 0% control electric generator, n load circuit connected thereto, and me no i'nn'intaining the voltage of said generator snhstantinlly constant comprising an electromagnetically operated hralre for comprisi g; magnet windings rolled by the gcner voltage and by n: load current,- rcspectiyely.

' e system oi control, a turbine to wint my; causes the series coil to overpo. r the shunt. coil. and the man"; netic dr: produced thereby increases with" the electrical load and tends to reduce the the ;L=;enc.rz= or, and thus prevents it,

wring; r nt. lhe

' nnd in the ser drag .icFstea-ni under constant pressure hr ed, so electric generator connected theresp accordingly the to a load; circuit connected to said generator so. t when a )Zlli; and means for maintainin the volts ":2 oil 1 I: I 1 J 1' 1 1 or tso that the said generator substantially constant comtrm 1 n on, the vol prising an electromagneticaily operated This is an under the joint control 0*? the .tage and by the load current res netizing mem comprising a magnetizing member brake for the generator under the joint control of the generator voltage and of the load current. a

5. In a system of control, a turbine to which steam under constant pressure is supplied, an electric generator connected thereto, a load circuit connected to said generator, and means for maintaining the voltage of said generator substantially constant comprising an electromagnetically operated brake for the generator comprising magnet windings controlled by the generator volectively.

6. Ina system of control, an e ectric generator, and an electromagnetically operated brake therefor comprising differential magnet windings controlled by the generator voltage and by the load current, respectively, and arranged to neutralize each other under normal full load conditions.

7. In a system of control, an electric generator, a load circuit connected thereto, and a magnetic drag brake for the generator comprising a magnetizing member excited by difl'erential windings controlled by the voltage of the generator and by the load current,

respectively, and a magnetic drag member within the ma 'netic influence of said mager and movable with the armature of the generator.

8. In a system of control, an electric generator, a plurality of translating devices connected in parallel with the generator, and a magnetic drag brake for the generator including a magnetizing winding controlled by the generator voltage and a bucking winding controlled by the load current, and arranged to neutralize the magnetic effect of the firstwindin under normal full load conditions, and a disk of conducting material mounted upon the armature shaft within the magnetic influence of said magnetizing windings. 7

9. In combination, a turbine to which steam under constant pressure is supplied, a generator connected to said turbine, a variable load connected to the generator, and a magnetic drag brake for the generator comrising windings connected in series with the lbad and in shunt to the generator respectively, and a magnetic drag, member carried by the armature shaft of said generator and within the magnetic influence of said windlugs.

10. A generator connected to supply energy to a variable load, means for driving said generator, a second load element normally inoperative and operable by said driving means, said second load element comprising a disk of conductive material mechanically connected to the shaft of said gen; erator-driving means and means forcreating a magnetic field through said disk, and means responsive to variations in load on said generator for varying the intensity of said magnetic field.

11. A enerator connected to supply a variable End, a brake for said generator, said brake comprising means for creating a magnetic field, the magnetic field created being normally ineffective to cause braking action, and automatically operative load actuated means for rendering said magnetic field effective to cause braking action.

12. In combination, a generator, a brake associated with said generator and comprising an energizing winding, and control means responsiveto variations in load on said generator and effective under normal operating conditions to insure minimum effects due to said brake energizing winding and'under abnormal operating conditions to insure maximum effects due to said brake ener izinr windin b b b disk of conductive material and means for producing a magnetic field through said disk, and means responsive to variations in load for varying the intensity of said field.

In witness whereof, (In/mans l. S'rEiN- MlCflZ has hereunto set his hand this 26th day of July, and REGINALD (ir. STANDEHWIOK has hereunto set his hand this 27th day of July, 1915.

STEIN METZ.

STAN DERWICK. 

